The invention relates to a ball bearing for linear motion including a ball cage with ball-carrying oval guideways and an outer sleeve receiving said ball cage. The sleeve has ball-carrying, axially parallel raceway sections for the loaded balls, each raceway section having a radially outward directed transition at each end or the respective raceway section.
A ball bearing of this type is disclosed in German Pat. No. 1,916,164, in which the ball-carrying transitions of every raceway section form, together with said section, a rigid unit constituting a unitary part of the outer sleeve, that is to say, every ball-carrying raceway section is rigidly joined both at its longitudinal edges and at its two ends to the outer sleeve. When under load, every raceway section therefore deforms nonuniformly, that is to say, not parallel to the longitudinal axis of the outer sleeve. As a result of this, irregularities which may occur in operation cannot be compensated. Moreover, balls ascending the transition which are being loaded, and the balls descending the transition which are being unloaded are subjected to increased rolling friction, and also to sliding friction. This causes wear not only to the balls, but also to the outer sleeve.
Moreover, U.S. Pat. No. 4,062,602 discloses a ball bearing, each of whose ball-carrying, axially extending parallel raceway sections has a ball-guiding groove wherein the loaded balls hug the bottom of the groove.